Down Pipe with Presilencer - 1989-91 RX-7 Coupe Non-Turbo (equipped with Automatic Transmission) - The 1986-92 13B 6-port engines, in stock form with the factory fuel injection, produces similar power gains with either our Header/Presilencer combo or our RX-7 Down Pipe/Presilencer combination. If you have no intentions of installing our Holley intake System (or any other aftermarket carb set-up), we recommend the use of the RX-7 Down Pipe/Presilencer combo since it offers a slightly quieter exhaust note, is easier to install and less costly. If you are intending to upgrade the intake or fuel injection system, the Header/Presilencer combo offers the greatest performance potential.
The Down Pipe/Presilencer combination incorporates a 2.5-inch O.D. Down Pipe and our perforated stainless steel core and stainless steel wool-packed Presilencer to boost power approximately 13% - an 18 horsepower increase on a 1987 RX 7- and maintain a comfortable exhaust noise level during full power driving.
The replacement pipe connects to the factory exhaust manifold, and the presilencer connects to the factory Y-pipe, replacing all catalytic converters and intermediate tubing. It is not possible to use just the down pipe to replace only the catalytic converters. The use of the presilencer is required to complete the connection to the y-pipe. Although a short length of tubing can be substituted in place of the presilencer, we so not offer (or suggest) this due the unacceptable increase in exhaust noise.
The down pipe is equipped with a mounting flange for the oxygen sensor. This kit includes all necessary mounting hardware, air control & check valve cover plate, and gaskets (3 Replacement Pipe-to-Presilencer gaskets). We also offer the Down Pipe separately for those building custom exhaust systems.
Replacement Rubber Exhaust Hangers
It is our experience that the stock rubber hangers that support the exhaust system can deteriorate and crack with age. We suggest the replacement of these hangers when installing replacement exhaust components. If needed, we provide the Mazda replacement rubber hanger for use with your Presilencer unit.